The present invention relates to a wave-guide circulator, for hyperfrequency waves, in which the gyrator may be integrated. The circulator of the invention is a model in which the power may reach and even exceed a kilowatt, in a frequency range between 1 and 100 GHz.
In its general definition, a circulator is a hyperfrequency component with a certain number of ports, three at least, which transmits the energy which it receives through one port to another port. This component has the property of non reciprocity, that is to say that if the direction of the incident energy is modified, the function of the input and output ports is not exchanged. This condition of non reciprocity is introduced by using in such component a gyrator comprising ferrites. These latter ceramic magnetic materials formed mainly by metal oxides which differ however from conventional metal magnetic materials by the fact that they are non conducting and have low losses of magnetic origin at hyperfrequencies.
Among the different classes of circulators, those said to be with junction consist of a junction with three or four ports formed as a wave guide in which there is inserted, at the center thereof, at least one ferrite bar subjected to an external transverse magnetic field.
Wave-guide circulators are formed of a metal body which is either integrally machined in the mass, or is welded, and whose body is:
either in several assembled parts: it is then easy to adhere thereto and position the ferrites, PA1 or in a single piece, which means that access cannot be had to the inside of the body, for fixing a gyrator there except through the ports of the circulator, which involves then removal thereof from the equipment in which it is in service. PA1 the two main faces of the wave-guide are pierced with holes, one facing the other, and centered on the center of symmetry of the junction, PA1 a one-piece gyrator passes through the wave-guide, through holes formed in the main faces of the wave-guide, PA1 the cooling plates hold the gyrator immobile in the wave-guide.
Wave-guides are made either from welded metal sheet, or are molded and it is difficult to accurately position therein and fix therein the ferrite part or parts of the gyrator, all the more so since wave-guides do not have--except for the ports--slits or air gaps which have the double drawback of having a high impedance and of causing a hyperfrequency leak, which is dangerous for the user.
It is then an object of the invention to solve the problem of integrating a gyrator in a wave-guide structure, without requiring access to the inside of the wave-guide.
It is another object of the invention to solve this problem in the case of a one-piece wave-guide, welded or molded, but formed to two separable half shells.
It is a further object of the invention to solve this problem in the case of high power circulators, having on their main surfaces air or liquid heat sinks.
It is also an object of the invention to provide an industrial power circulator insensitive to dust, through the absence of free gaps between the ferrite.
Finally it is an object of the invention to provide ready and economic integration of the gyrator in the circulator without additional insertion losses or parasite radiation.